Add secret.Warn() calls for all silent anomalous conditions

Audit of the codebase found 9 locations where errors or anomalous
conditions were silently swallowed or only logged via Debug(). Users
should be informed when something unexpected happens, even if the
program can continue.

Changes:
- DetermineStateDir: warn on config dir fallback to ~/.config
- info_helper: warn when vault/secret stats cannot be read
- unlockers list: warn on metadata read/parse failures (fixes FIXMEs)
- unlockers list: warn on fallback ID generation
- checkUnlockerExists: warn on errors during duplicate checking
- completions: warn on unlocker metadata read/parse failures
- version list: upgrade metadata load failure from Debug to Warn
- secrets: upgrade file close failure from Debug to Warn
- version naming: warn on malformed version directory names

Closes #19

internal/cli/info_helper.go

@@ -4,6 +4,7 @@ import (
 	"path/filepath"
 	"time"
 
+	"git.eeqj.de/sneak/secret/internal/secret"
 	"github.com/spf13/afero"
 )
 
@@ -28,6 +29,8 @@ func gatherVaultStats(
 		// Count secrets in this vault
 		secretEntries, err := afero.ReadDir(fs, secretsPath)
 		if err != nil {
+			secret.Warn("Could not read secrets directory for vault", "vault", vaultEntry.Name(), "error", err)
+
 			continue
 		}
 
@@ -43,6 +46,8 @@ func gatherVaultStats(
 			versionsPath := filepath.Join(secretPath, "versions")
 			versionEntries, err := afero.ReadDir(fs, versionsPath)
 			if err != nil {
+				secret.Warn("Could not read versions directory for secret", "secret", secretEntry.Name(), "error", err)
+
 				continue
 			}